Global patent index - EP 1028438 A1

EP 1028438 A1 2000-08-16 - METHOD OF MANUFACTURING R-Fe-B BOND MAGNETS OF HIGH CORROSION RESISTANCE

Title (en)

METHOD OF MANUFACTURING R-Fe-B BOND MAGNETS OF HIGH CORROSION RESISTANCE

Title (de)

HERSTELLUNGSVERFAHREN VON R-FE-B VERBUNDMAGNETEN MIT HÖHE KORROSIONSWIDERSTAND

Title (fr)

PROCEDE DE FABRICATION D'AIMANTS A LIAISON R-FE-B PRESENTANT UNE HAUTE RESISTANCE A LA CORROSION

Publication

EP 1028438 A1 (EN)

Application

EP 98947935 A

Priority

  • JP 9804718 W
  • JP 31643697 A

Abstract (en)

A method of manufacturing R-Fe-B bonded magnets, capable of forming various corrosion resisting films on a R-Fe-B bonded magnet uniformly with a very high bonded strength so as to attain such a very high corrosion resistance thereof that prevents the bonded magnet from being rusted even in a long-period high-temperature high-humidity test; comprising barrel-polishing a porous R-Fe-B bonded magnet by a dry method using as media an abrasive stone formed by sintering inorganic powder of Al2O3, SiC, ZrO and MgO, or a mixture of an abrasive for metal balls and vegetable media, such as vegetable skin chips, sawdust, rind of a fruit and a core of corn, or a mixture of vegetable media the surfaces of which are modified by the above-mentioned abrasive and the above-mentioned inorganic pulverized bodies, so as to enable a surface of the magnet to be smoothed and sealed; or immersing a magnet material in a neutral or alkali bath so as to enable a layer of electroless plating to be formed thereon; or subjecting a magnet material to electrolytic plating so as to enable a film of markedly high bonded strength and dimensional accuracy to be formed thereon, whereby an object R-Fe-B bonded magnet of a high dimensional accuracy and a high corrosion resistance is obtained.

IPC 1-7 (main, further and additional classification)

H01F 41/02; B24B 31/14

IPC 8 full level (invention and additional information)

B24B 31/14 (2006.01); H01F 41/02 (2006.01)

CPC (invention and additional information)

B24B 31/14 (2013.01); H01F 41/026 (2013.01)

Designated contracting state (EPC)

DE FR GB NL

EPO simple patent family

EP 1028438 A1 20000816; EP 1028438 A4 20010117; EP 1028438 B1 20050420; CN 1148764 C 20040505; CN 1278358 A 20001227; DE 69829872 D1 20050525; DE 69829872 T2 20050922; KR 100371786 B1 20030212; US 6365030 B1 20020402; WO 9923676 A1 19990514

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